Thread-cutting mechanism for sewing-machines.



No. 885,310. PATENTED APR. 21, 1908.

. E. B. ALLEN:. I THREAD CUTTING MECHANISM FOR SEWING MACHINES.

APPLIOATIOH FILED NOV. 23, 1905.

wi l neoocp 6, Svwcwl'oz i e014 attaining/E I 2 1110. 885,310. 'PATENTED APR. 21,1908.

5. 'B. ALLEN. THREAD CUTTING MECHANISM FOR sswme MACHINES.

APPLICATION FILED H0123, 1905.

4 SHEETS-SHEET 2 f 15 21 45 y I r if "'"nm, 12

, g v'wmfoz .No, 885,310. PATENTED APR. 21, 1908.

' B1B. ALLEN.

THREAD CUTTING MECHANISM FOR SEWING MACHINES.

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6 vita/moses No. 885,310. I PATENTEDY'APRPZI, 190a;

E.B.ALLEN. THREAD CUTTING MECHANISM FOR SEWIN'GMAGHINBS.

APPLICATION FILED NOV; 23-, 1905.

. 4 SHEETS-BEBE! l.

Q l i 16 57 3690 o 15 -which the former antomaticalh actu- UNITED PATENT ()FFICE.

ED\\'ARD l5. ALLEN, Oi ELIZABETH. l'llW JERSEY, ASSIUNUR TO THE .SlNUrER MANUFACTUR- INU CUMPAN Y. A (OltltlliAllON ()l" NEW JERSEY.

THREAD-CUTTING MECHANISM FOR SEWING-MACHINES.

Specification of Letters Patent.

Patented Apri121, 1908.

Application filed November 23, 1905. Serial No. 288,6el'i'.

Be it known that l, l lowano B. ALLEN. a citizen of the United States, residing at Elizabeth, in the county ol Union and State l of New Jersey, have invented certain 'new and useful lmprovcanents in 'lln'catht utting Mechanism for Sewin yliachines, of which the following is a speciiirl-ation, reference being bad therein to the accompanying i'lrawings.

This invention relates to means for eut 5 ting the threads in that class of sewin ma chines, and particularly those provided with stitch-formirn, mechanism employing upper and lower threads, which are adapted to produce groups of stitches: and it has for its primary object to provide cutting mechanism for both upper and lower threads which shall operate in such manner as to avoid leaving the out thread end or ends upon the face or upper surface of the work. 7

lit has for its further object to provide special means for cutting the needle thread above the work.

To this end, the invention. in its prel'errcd lorm, comprises indepcinlentl operable upl per and lower tlu'eada-utting mechanisms, ol'

l l l l l l l ated. at the end oi each stitching operation and the latter manually" operated thereafter, whereby the shuttle thread remaining taut alter the severing oi' the nwedlc thread will tend to draw the cut end ol' the latter 1 downward below the upper face at the maj terial, while the provision ot a lower thread pulloll' acting in conjunctiim with and in advance of the cutter [or severing the lower i thread positive-l insures the drawing down i beneath the material of lhecnl had at upper thread. g i l The invention l'urthr-r includes a w rk-- clamp carrying ih d-ruliinc and nippingfi members and c ntrolled in its operation b v i a spring which is compressed by the l'ccninu movement of the \i'odw-lamp in the l'ormation ol a group of st .chcs and controlled by a species oiescapennan actua ed by a con nection through the stop-moti n device with. l a cycle cam connected with lilt stilch-l'orming mechanism.

The invention will be understood by .relerence to the annexed drawings. in which I Figure 1 is an elevation of one side of a button-hole sewing machine embodying the presentimprovements, and 2 a bottom 5 View of the-same; 3 an elevation of the l opposite side of the machine from Fig. 1 with a portion of the bed-plate and base by which the same is supported broken away to expose certain parts inelosed therein; and l a plan of the machine with the upper 5 portion of the ln-acket-arm and parts carried thereby removed.

Fig. 5 is an elevation upon an enlarged scale of the tripping device for the upper thread-cutter and the tension release, and Fig. e a side view of the tension release. .l igs. T and 8 are detail views showing portions of the connections be- 1 tween the upper thread-cutting mechanism and the stop-motion device. Fe. 9 is a plan of the forward portion of the bed-plate and the upper thrombi-titling mechanism in a diil'crent position from that represented in Fig. l. bottom view of the upper clamping member oi the work-holder showing the thread-cutting and nipping devices applied thereto, and Fig. i2 is a detail view of the upper tln'ezul-cul'ting and nipping; blades. Fig 13 is a detail sectional view oi" the upper workclamp member and needle with the cut end ol the needle thread held by the. thread-nil pine blade. Fig. H a detail bottom View upon an enlarged scale of the lower threadcntter and pull-oil.

'lhe present improvements are shown embodied in a straight buttonhole machine of f the well-lnown Sinner type, such as that represented in the l F. patent granted to inc ltcccmbcr 5, 190:), No. 806,231, and is rovided with the usual bracl et-arm l rising l om the rear end ol' the bedplato 2 supporledby the base 3.

As represented herein the stitch-forming mechanism comprises the ll.\ll2ll eve-pointed necdlel carried b the necdlc-bar 5 mounted ill the usual horniontallv swinging lrame and deriving its 'i'ertical reciprocating movements trom the main shalt ti mounted in the hori- Zuliirll portion ol the bracket-arm 1. The needle coi'jipcraies with a shuttle carrying the under lhrcmhcnsc T and mounted in a racoway to receive oscillating movements from the rock-sha t 9 having connections through the roclicr. l (l and link ll with the main shaft, in a manncr well-known. The work-carrier is l'ormcd with a lower member consistinggof the lrnigitmlinally movable slide-plate, 12

having an elongated opening 13 surrounding the needle-throat, and. an upper jaw or elongated needle-opening ifiand ried by Fig. 10 is a. top view and Fig. 11 a 1.19. clamping loot l-i snmlarly proxiclellwitli an means of a pair of spring arms 16 secured to a block 17 pivotally mounted by means of a horizontal pin 18 upon a hinge-block 19 fixed upon a lateral extension of the slide-plate 12. The carrier comprising the arm 16 and block 17 is provided with a bacluvardly extending operating lever 20 by which the foot 1-4 ma y be raised for introduction and removal of the work, but is adapted to close upon the lower clamp member under the action of its spring 100 upon the release of the lever 20. member 22 is herein termed a cycle-cam as its function is to ell'ect the relative feeding movements between the stitch-forming mechanism. and the work holder and to initiate and control the timing of operation ol' certain other parts of the machine. The longitudinai slide-plate 1:2 is mounted in suitable guide-ways in the transverse slide-plate 2.1, and each of such plates is provided with the usual connections with the teed-cam 22 from which their respective longitudinal feeding and lateral shifting movements are derived.

As represented particularly in Figsv 10, 1 1, 12 and 13, the upper clamp member 1-1 provided internumiate and parallel with its upper and lower aces with a slot 23 to receive the separat thread-chimping and nipping blades 4 and mounted upon the lower end of the vertical shaft 213 provided above the member 14 with a fixed collar 27 having the crank-arm For convenience in the insertion and removal or the cutting and nipting blades, the lower side of the loot i l is rovided with a iletachable portion 29 sered the em by means of screws 30 i he crank arm is connected with one of a rod 31. disposed in the direction of longitudinal moven'ient of the work-holder and surmorted intermediate its ends by the rigid arm which serves in conjunction with the lixed collar 33 upon the rod 31 as a. stop to limit the endwise motion of the rod under the action of the spring 34 connected at one end with the arm 3; and at the other end with a pin upon another lined collar 35 upon the rod 31. To produce the necessary endwise movements of the rod 31 for actuating the nipping and cutting blades 24: and 25, a .lon itiulinal rock-shalt 36 is mounted in bearings pro vided therefor in a. bracket 37 secured upon the bI2u'l(l--;l1lil 1, said rocl shaft having lived. to its forward end a lateral arm 38 carrying at its outer end a latch-plate 39 pivotally mounted thereon by means of it screw pin 41) which carries a lateral pin -11 engaged by the free end of a spring l2 having its iixed end attached to the arm 38 by means of a screw 43, whereby the inner end oi the latch-plate 39 is yieldingly pressed against a lateral stop-pin upon the arm 38 and the latch-plate is normally maintained in line with its carrying arm and with the rod 31.

The rear end of the rock-shaft 36 is pro- Vided with lateral ttll'll'ls provided with a cylindrical socket 46 which carries a longitudinallymovable pin 17 with collar 18 intermediate its ends and between which and the inner end of a perforated screw-plug 49 at the rearward end of the socket slfiois interposed a spring 50 tor yieldingly maintaining the pin 47 in its forward position for engagement with the top ol" a collal 51 iixed upon the stop-motion plunger rod 52 surrounded by a spring 53 interposed between said collar 51 and a bearing 54 for the plunger rod in the slotted vibrating stop-motion lever 55 mounted upon the center screws 55 whereby the plunger rod is pressed normally upward for operative engagement with the stop-motion cam so mounted upon the hub of and having the usual yielding connection with the lixed pulley 57 upon the main-shaft 6, the stopmotion device herein represented being that of my prior United States patents No. 767,539, ol'August 1t, 1004, and No. 806,231., of December 5, 1905.

llhen the stop-motion lever 55 is tilted forwardly in opposition to its actuating spring 58, as represented in the drawings, the upper end of the plunger rod is drawn out of the path ol movement of the cam 55 and its lixed collar 51 is withdrawn from contact. with the pin 4-7, and the mechanism is adjusted tor the stitching operation, the belt-guiding linger 52') carried by an upwardly-projecting arm (50 ol the lever 55 maintaining the belt upon the lixed pulley 57 lot such purpose. in the rui'ining position of the parts corresponding with such position oi the stop-motion lever, the arm 35 is extended toward the axial line ol' the rod 31 and its latch-plate 39 rests yieldingly against such rod by which it is temporarily displaced from its normal positionv represented in dotted lines in Fig. 5. As the work-clamp moves forwardly with the normal feeding movement communicated to .it by the feed-cam 22, the rod 31 is carried with; it and its end passes the latch-plate 39 which is thereby enabled to drop in behind it under the action of the spring -12. In the return. teed-movement of the work-clamp to initial position for the stitching of the second side of the button-hole, the rod 131 is detained by the latch-plate 3.), while the cutter shaft 26 continues its travel with the clamp member 14 whereby the angular relation of the crank-M11128 and rod 31 is gradually changed and thus causes the cutting and nipping blades 24 and 25 to be slowly retracted from their operative transverse position at the end of the needle-opening 15 (Fig. 11), and to assume their inoperative position at the side of the needle-opening 15, represented in dotted lines in Fig. 10, the spring 34 being thereby placed under increased tension for s ul. seq1 ient performance of its primary function.

When the latch-lever 61 is shifted by actuation of its tripping lug 22 carried by the pending arm 89 is simultaneously shifted. laterally to vibrate the lever 86 in opposition to its retaining spring 99, and the slide-bar 73 is thereby given transverse shifting movements. As the screw S2 engages the pull-oft lever intermediate its ends, it is evident that the latter receives a longer stroke than the knife-lladc 76, and as the operative portion S4 of such pull-cit lever is normally adjacent the portion 76 of the cutting knife, it will be seen that the pull-oii lever is caused to act upon the lower thread considerably in advance of the knife, so as to draw oit the requisite length of such thread from the thread- .case before the operative edge of the knife has ad anced to cutting position, as repre sented in Fig 14, from which it will be observed that the opening of the clamp to remove the work causes the successive pulling ed and cutting of the under thread.

h'lechanisms have heretofore been devised for cutting practically at the same time the upper and under threads of a multiplethread sewing machine, but such devices have been to a certain extent inetiective in that no provision has heen made for drawing the cut end of the upper thread downward beneath the work. By first cutting the up per thread and then allowing an interval of time in which the elastici" of the taut lower thread may act in drawing downwardly the cut end of upper thread, a tendency is created tor the correction of this defect, while the addition of a positive under thread pull ott' device acting subsequently to the cutting ol the upper three l and prior to the action of the lower tlnrcad-cutter insures the withdrawal of the cut thread end from the face of the material.

While the means i'or successively actuating the upper and lower thread severing mechanisms herein shown and described are con sidered to he the prcicral'ilc embodiment of the present improvement, it evidently immaterial to the ct nee of the invention whether both upper and lower thread severing mechanisms be actuated automatically or both nninually, or the one automatically and the other manually, til whether such mechanisms be actuated even by independ ent means, so long the one is actuated in advance of the other to enable the unsevered thread to draw ither par tialiy or wholly beneath or through. the work he end of the previously severed thread prior to the sever ing of such theretofore unsevered thread.

In the emplo ment of an autoi'naticallv acting cutting device for the lower thread, especially in connection with a pull-ofi' device, the sudden pull upon the lower thread necessary in the quick action of the mechanism has produced an objectionable spilling of the "lower thread from its bobbin, which is entirely. obviated by the manually-operated device herein shown and described. Therefore, the present improvement adapts the machine for quickly and eiiectively cutting the upper thread at the end of each stitching operation while offering every advantage with absolutely no unnecessary loss of timein severing the lower thread in the most advantag'eous marmer.

While the present improvement is shown herein ap lied to a buttonhole sewin machine oi' tne class described, it is evidently well adapted for incorporation in other classes of sewing machines with equal advantage, and the )resent invention is not therefore to be un erstood as limited to the particular embodiment and details of construction herein shown and described.

Having thus set forth the nature of the invention, what I claim herein is,

1. In a sewing machine comprising sewin instrumentalities, needle and looper threa severing devices located respectively on opposite sides of the work, means for operating said severing devices whereby one of the threads may be severed before the other while the work is in its normal position to be stitched in. the machine, and whereby inthe interval between the severing operations the unsevercd thread may operate to draw the end of the severed thread through the face of the work upon the side on which it was severed. J

2. Inasewing machine for forminggrou sot stitches, the combination ,With stitc i forming devices comprlsmg upper thread mechanism and under thread mechanism, a stop-motion device for controlling the operation of said stitch-forming devices and a cycle cam for controlling the operation of said stop-motion device, of independent upper and lower thread severing devices having their threadengaging members spaced to admit the work between them and thus disposed at opposite sides of the work, automatic lly-acting means for actuating the upper thread severing device at the end of a stitching operation, and manually-operated means whereby the lower thread severing device may be actuated after the stitch-forming mechanism comes to rest and after the upper thread is severed 3. In a sewing machine for forming grou s of stitches, the combination with stitc forming devices comprising upper thread mechanism and under thread mechanism, a self-closing work-clamp and manually-con trolled means for opening the same, a stopmotion device forcontrolling the operation of said stitch-forming devices and a cycle cam for controlling the operation of said sto motion device, of independent; upperan lower thread severing devices, automaticallyacting means for actuating theupperthread severing device at the end of a stitching o H whereby a single manual actuation of the same effects the opening of" said clamp and the operation of the lower-thread sevrring stop-motion device for controlling the operation of said stitch-forming devices and a cycle cam for controlling the oration of said sto -motion device, of inc ependent upper an lower thread severing devices having their thread-engaging members spaced to adthe worhbetween them and thus disposed at opposite sides of the work, a connection between said upper thread severing device and the stop-motion device whereby the operation of the latter in arresting the stitch-forming devices causes the operation of said upper thread severing device to sever the upper thread, and manually-operated means whereby the lower thread severing dcvice may be actuated after the stitch-forming mechanism comes to rest.

5. In a sewing machine for'forming groups of stitches, the combination with stitchforming devices comprising upper thread mechanism and under thread mechanism, a

st0p-motion device for controlling the ope rat1on ofsa1d stitch-forming devices and a ovole-cam for controlling the operation of said sto -mot1on devices, ol independent upper an lower thread severing devices, a lower thread pull-oft, auton'iatimlly-aeting meansfor actuating the upper thread severing device at the end of a stitching operation, and manually-operated means whereby said pnll- OE and lower thread severing devices may be actuated after the severing of the upper thread to successively pull oil and sever the i lower thread.

6. In'a sewing machine tor forming grou s of stitches, the combination with Eitllillforming devices comprising upper thread mechanism and under thread mechanism, a work-clamp relatively movable in respect of said stitch-forming devices, a stop-motion device for controlling the operation of said stitch-forming devices and a cycle-cam for controlling the operation of said stop-motion device and for communicating relative feed ing movements between said workc,lamp and stitch-forming devices, of an upper thread severing device carried by said work-clamp and provided with s ring pressed actuating means, and a lower tiiread severing device, a rock-shaft deriving rocking movements from the stop-motion mechanism and provided with a lateral arm adapted to cooperate with the actuating means of the upper thread severing devicein the compression of its spring and to release the same to enable it to perform its normal function, a sleeve mounted. loosely upon s id rock-shalt and having two arms one of which is opcrativelv connected with the work r-in mp for opening the same :"nd the other is provided with a positive connection with said lower thread severing dcvice, and means l'or roelring said sleeve to open the worlcclamp and sever the lower threa d alter the upper thread has been automatically severed through its connection with the stopmotion device.

, 7. lnascwingmachine l'orforminggrou s 01' stitches, the combination with stitcrforming devices comprising upper thread mechanism and under thread mechanism, a work-clamp relatively movable in respect of said stitch-torming devices, a stop-motion device for controlling the operation of said stitch-forming devices and a cycle-cam for controlling the operation of said stop--motion device and for communicating relative feeding movements between. said work-clamp and stitchd'm'ming devices, ol' an uppcr thread nipping and severing device carried by said worlvclani 'i at the portion thereof through which the stitchd'orming devices initially operate, and actuating means therefor comprising an operating member also carried by said worleclamp, a lower thread severing devicc mounted in lixed relation to said stitchforming devices, automaticnlly-acting means for controlling the upper thread actuating means to release the upper-tbread-end after a material relative movement of the workclamp and stitch-forming devices from initial starting position and to again successively nip and scvcrthe upper thread upon the return ol such relatively moving parts to initial position at the cod ol' the siiichd orining operation, and .nnimiali v- .ipcratcd incurs whereby the lower thrcndsevcring device may be actuated alter the nipping and severing of the needled-bread.

S. in a sewing machine for forming groups of stitches, the combination with stitch-forming devices comprising upper thread mechanism and complemcntal stitch-forming mechanism, a work-clamp relatively movable in res )ect of said stitch-forming devices, and a cycle-cam l'or connnuiiicatiug the relative feeding movements between said workclamp and stitch-forming devices, of a thread severing device carried by said work-clamp, actuating means therefor comprising a springprcssed reciprocating rod also carried by said work-clam a stop-member disposed normally in tie path of endwise movement of said springpressed rod for arresting the pressed rod and the latter is thereby perinitted to return to initial relation and theresevering device carried by said work-clamp,

actuating nieans theret'orcomprising a springpressed reciprocating rod also carried by said work-clamp, a rock-shaft and operative cottnect-ions between the same and said cycleeam whereby the latter is roclv'ed at the comering blades. the operative edge o pletion of a stitch-Forming cycle. and a lateral arin upon said rock-shalt provided with a movably-mounted latch-plate adapted to serve normally as a. stop for said spring pressed rod, whereby the movement of the clamp in respect of said lateral arm causes the detention of said rod by the latch-plate to effect the o iening ol the thread nipping and severing device, while the subsequent actuation of the rock-shaft causes the movement of its said lateral arm to release the spring-pressed rod and permit the same to return the nipping and cutting device to initial operative position for engagement with the thread. f

10. In a sewing machine for lol'tnittg' groups of stitches, the combination with stitch-tortuing devices comprising upper thread mechanism and coniplemental stitcl'l-l'orming mechanism, a Work-clamp relatively movable in res ect of said stitch-forming devices. and a eye e-cani' for commtmicating the relative. feeding movements between said work-cla mp and stitch formin'gdevices of a thread severing device carried by said work-clamp. actuating means therefor eomprising a springpressed reciprocating rod also carried by said Work-elati-ui, a rock-shaft and operative connection betXveen the same and said ycleearn whereby thelatter is Y'Ut'htil at the completion of a stitch-Forming cycle and a latoral arm upon said rock-shaft provided with a pivotally-mounted springpressed latchplat-e adapted to serve normally as a. stop for said spring-messed rod, whereby the movement of the clamp in respect of said lateral arm causes the detention of said rod by the latch-plate. to ell'ect the openfiig ot' the,

thread nipping and severing d'evice, while the subsequent actuation of the rook-shalt causes the movement of its said lateral arm. o release 'the spring-pressed rod and permit the same to return the nipping and cutting (twic to initial operative-position for en s agement with the thread. H in a sewing machine for forming groups ol' stitches, the combination witlf sti'ii of stitehes, the combination with stitch-forniing devices comprising upper thread mechanism and complemental stitch-forming mechanism a work-clamp relatively movable in respect ot' aid stitch-forming devices. the upper member of said clamp being provided with a needle-opet'ting and with a. transverse slot parallel with the operative tare of the same, and a cycle-cam for communicating the relative teeding movements between said work-clamp and 'tltt'li-tflfhlilltj devices, of a thread nipping and severing d-" i e comprising overlapping thread nippi" and sevu former being disposed in advance of tha i' the latter. a vertical roclg-shal't mountct upon said work-clamp member and having aid blades [iXed-ttpon its lower end within :aid transverse slot and a crank-arm upo" its upper end. a spring-pressed reciprocatingv rod connected with the crank arm of said shatl't andsupported upon said upper clamp-memher, a stop-member disposed normally in the path of endwise movement with the worleclamp ol' thespring-pressed rod for arresting the movement of the latter in the traverse of said work-clamp for causing it to throw the thread nipping and cuttingblade's baehwardly into inoperative position, andmeans intermediate said stop-member and cycle-cam whereby said stop-membenis disengaged at the end of the stitch-forming operation than said spring-pressed rod and the latter j is thereby ptn'mitted to return to initial re lation and to cause the nipping and severing of the thread by action-of said ni )ping and cutting blades in conjunction with the respective adjacent edges of the transverse slot in the upper work-clamp member in which. they are disposed.

' 1;. ln asewing machine l'orl'orming groups of stitches, the combination with stitchl'oi-ming devices comprising upper-thread mechanist'n and under-threzul mechanism, of an up'per-thrtanl severing device and an under-thread severing deyice having its threadengaging portion spaced from that of the upper-thread severing device to admit the work between them and thus disposed at the opposite side of the work tromthe same, and indep ndent ly. operable actuating means for said severing devices. whereby the upper thread may be severed in advance of the lower thread to permit the cut. end of upper thread to be. drawn below the face of the work by mtnusml 'the lower thread previous to the severingol' the latter. t x

1:). ln-asewingtnachinet'orlorming grou s forming devices comprising upper-thread mechanism and under-thread vi'nechanisnt, of an upper-thread severing device and an undert hread severing device having its threadengaging portion spaced from that of the upper-thread severing device to admit the work site side of the work from the same, and sur between them and thus disposed at the oppocessively operable actuating means for said severing devices, whereby the upper thread may be severed in advance of the lower thread to permit the cut end ol upper thread to be drawn below the face of the work by meansof the lower thread previous to the severing of the latter.

14. In a'sewingmachine for forming groups of stitches, the combination with stitc forming devices comprising upper-thread mechanism and under-thread mechanism, of an up wr-thread severing device, an underthread severing device, an under-thread pulloff, a connection between the under-thread severing device and the pull-off whereby the latter is caused to operatively cn age the thread in advance of the former, and actuating means for said upper and under thread severing devices whereby the upper thread may be severed prior to the engagement of the lower thread by the pull-o'll' and lowerthread severing device.

Hi. In asewing machine for forming groups of stitches, the combination with stitchl'orming devices comprising upper-thread mechanism and under-thread mechanism, of an upper-thread severing device and an under-thread severing device having its thread-engaging ortion spaced from that of the upper-thread severing device to admit the work between them and thus disposed at the opposite side of the work froin the same, and actuating means whereby the lower thread severing device maybe operated after the operation of the upper hread severing device, thus providing an interval between the severing operations in. which the unsevcred lower thread ma operate to draw the severed end of upper t read below the face of the work.

In testimony whereof, I have signed my name to this specification, 1n the presence of two subscribing witnesses.

EDWARD B. ALLEN.

Witnesses:

HENRY J. MILLER, HENRY n. KORNEMANN'.- 

